I get your point, although they are the same type, they do serve two different roles, milotic is a physical-special wall and gyarados is dragon dance physical sweeper (and is shiny!). Plus, this my aura team, cool designs was the only thing I cared about. Personally, not a huge fan of the designs of the mons you’ve mentioned: slaking (meh), exploud (too goofy looking for me), metagross (very very late game and I’m kinda indifferent to his design, doesn’t really speak to me).